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6th-Geo time, fossil
6th Grade science quiz on geologic time and fossils
Term | Definition |
---|---|
superposition | The idea that younger rock lies above older rock. |
Absolute dating | Finding the exact age of an object using unstable atoms |
Relative dating | Finding if a rock layer is older or younger than the layers around it. |
Geologic column | Detailed series of rock layers of all known fossils and rock formations from around the world. |
Explain the four features of an index fossil. | Found worldwide Abundant Easily recognizable Alive for only a short period of geologic time |
What is the index fossil of the Paleozoic Era? | Trilobite |
Precambrian Time | Age of Earth Forming rocks, ocean, atmosphere forming |
Paleozoic Era | Age of Ancient Plants and Animals large jungle-type plants, large insects |
Mesozoic Era | Age of Reptiles (or dinosaurs) dinosaurs thrive and then become extinct |
Cenozoic Era | Age of Flowering Plants and Mammals most recent Ice Age, humans evolve |
What do fossils show scientists? | 1. What Earth and its environment was like in the past. 2. How Earth and its environment have changed over time. 3. What organisms lived in the past. 4. How organisms have changed with time. |
Paleozoic | Means “old life” |
Mesozoic | means “middle life” |
Cenozoic | Means “ recent life” |
Precambrian Time | time before the Cambrian explosion |
Phanerozoic Eon | almost all fossils and rocks found on Earth today formed during this time. Eon in which we live. |
What is a trace fossil? Give three examples | Footprints, burrows, droppings |
What is a body fossil? Give three items that may become a body fossil | Bones, teeth, shells |
Cast fossil | Formed when sediment fills an impression made by an organism and becomes rock. |
Mold fossil | An impression or imprint of an organism in sediment which turns to rock. |
Petrified fossil | When minerals replace all or part of an organisms tissues, such as bone or wood. |
Preserved remains | When animals are preserved in or close to their natural state as in amber, tar, or ice. |
Carbon films | Thin layer of carbon from the organism left behind in the rock. |
Fossil | The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock. |
Index fossil | A fossil that is used to establish the age of a rock layer |